As those of you with an interest in MySQL may have seen, I’ve recently surged into the list of “Most Active Authors” on Planet MySQL, alas I’m not as prolific a blogger as it may seem, and this is purely down to an error with the feed I submitted to Planet MySQL. Having recently joined [...]

OSCon Data and OSCon videos
The Technocation youtube playlist, as of the time of this publishing has 18 videos, mostly from OSCon Data, is at http://www.youtube.com/playlist?list=PLE0AEC3980A198DA0

The O'Reilly YouTube playlist, as of the time of this publishing has 84 videos, from OSCon, OSCon Data and OScon Java, is at http://www.youtube.com/playlist?list=93FC98105B19725C

Note: There are no overlaps in the playlists, so that's over 100 videos from the week so far!

read more

It’s Friday again (so soon!) and time for our TGIF contest, to give away a free ticket to Percona Live London. Before we do that, though, just what in the world does this output from SHOW INNODB STATUS mean?

Mutex spin waits 5870888, rounds 19812448, OS waits 375285

To understand this text, you have to understand how InnoDB handles mutexes. It tries a two-step approach to getting a lock on a mutex. First, a thread tries to lock the mutex. If the mutex is locked by someone else, then the thread does a so-called spin wait. This means that it repeatedly checks “are you free? are you free? are you free?” in a loop. If this doesn’t work after a while, it gives up and goes to sleep until the mutex is free. I’m simplifying this a lot, perhaps too much, but it’s a topic that would take a long blog post to explain correctly in detail. The related source …

Don’t restrict your database blogging diet to just your blog reader or to your casual surfing on the net. Scour the brave bold world of database blogs from end to end. Huh? difficult? That is why we have brought you another Log Buffer Edition. Covering Oracle technologies to the SQL Server forays before culminating at [...]

In my last post, I provided a short review of what I have been working on in the past few months since I joined the Oracle Linux team. Now it's time for a summary of upcoming events! Looking forward, I already have a few more things lined up:

I'll attend and speak at the Oracle OpenWorld 2011 conference in San Francisco in October. I have a joint session with Chris Mason titled Overview: New Features in Oracle Linux 6 where we'll cover the latest developments. I have another joint presentation with my colleague Rob Young from the MySQL product …

Despite my best intentions, I haven't posted on this blog for a while, which is a shame! I've become busy writing on so many other places since I moved into my new role in the Oracle Linux product management team in April. I've learned a lot and I am feeling quite at home here! The team is excellent and very nice to work with — I am slowly getting the "Big Picture".

But even though I've been neglecting this blog, there are a lot of things that are publicly visible and document some of my activites:

I've created two podcasts for the Oracle Linux podcasts:

• OCFS2: Features and Benefits
• …

From time to time I see articles in defense of natural primary keys against surrogate keys.I don't take an immovable stand on either side, as I have seen good cases for both. In general, I like the idea of a natural primary key, when I see one that it is really natural. Quite often, though, a natural primary key has proved itself faulty. And most of the times, when such faults happened, it was because of limited understanding of the data. I like to describe this kind of misinformation as data analysis culture clash.When choosing a natural primary key, one should consider which element, or group of elements, are unique in a given set. Not only that, they must be immutable, at least within that set.For example, in a group of people, we may assume that a combination of name, surname, date and place of birth is a good natural primary key. Well, no. It isn't, for several reasons. Read on for a few real cases.If we rule out the above combination, …

Have you ever had a spreadsheet file or a large .csv file that you wanted to manipulate, but you want more power than a spreadsheet program could offer?

Before I started using MySQL, I would usually throw the .csv file into a desktop database program, like FileMaker. FileMaker would allow you to import the .csv file and it would automatically create the column headers for you. Recently, I was given a spreadsheet with 27,000 rows in it. I still use FileMaker for some databases, but I wanted the power of MySQL to manipulate the information contained in this file. So, I could have easily just typed out the database column names manually into a MySQL “create table” statement, guessed at the types and sizes of the columns and then imported the .csv file. Instead, I decided to write a Perl script to do the dirty work for me. Plus, this spreadsheet had 45 columns of varying lengths. Ouch.

Please keep in mind that this was a quick hack. …

We don’t pay enough attention to Hadoop.

By “we” I mean DBAs, the rest of the world is paying plenty of attention to Hadoop. Recently, I started asking my customers and fellow DBAs about Hadoop adoption in their company. Turns out that many of them have Hadoop. Hadoop shows up in large companies and small ones, in established industries and in startups. Its everywhere.

The way Hadoop shows up in all companies, and the way DBAs don’t pay Hadoop much attention, reminds me a lot of how MySQL started showing up in the enterprise. It didn’t start by DBAs showing up one morning and telling their managers:
“There’s this new open source database. Its not as stable as Oracle and it doesn’t have all the features we need, but man – its going to save us tons of money, and its pretty simple to manage.”

Nope, this never happened. What happened instead is that developers learned about MySQL, and it seemed …

Over the past two weeks I have been working on XtraBackup Manager as much as I can and I'm pleased to say that the command-line configurator is coming along very nicely!

There is now a generic "xbm" command that will be the way to manage hosts, storage volumes and backup schedules as well as doing restores, etc.

So far I have built the volume and host management in and will begin work on the backup schedules next!

Once this command-line interface is complete, I'll work to document it on the project wiki on Google Code and it should be ready for public consumption.

Here is a little preview of how it looks in action - forgive the ugly wrapping…

xbm@mslvlxbp01:~/xtrabackup-manager$ ./xbm


XtraBackup Manager v0.5 - Copyright 2011 Marin Software


Error: Context missing.


Usage: xbm <context> <action> <args> ... …